Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
  • C04B35/628—Coating the powders or the macroscopic reinforcing agents
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
  • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
  • C04B35/6303—Inorganic additives
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00034—Physico-chemical characteristics of the mixtures
  • C04B2111/00146—Sprayable or pumpable mixtures
  • C04B2111/00155—Sprayable, i.e. concrete-like, materials able to be shaped by spraying instead of by casting, e.g. gunite
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/0087—Uses not provided for elsewhere in C04B2111/00 for metallurgical applications
  • C04B2111/00887—Ferrous metallurgy
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
  • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
  • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
  • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
  • C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
  • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
  • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
  • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
  • C04B2235/3241—Chromium oxides, chromates, or oxide-forming salts thereof
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
  • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
  • C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
  • C04B2235/3418—Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
  • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
  • C04B2235/9669—Resistance against chemicals, e.g. against molten glass or molten salts
  • C04B2235/9676—Resistance against chemicals, e.g. against molten glass or molten salts against molten metals such as steel or aluminium

Definitions

• This invention relates to refractory compositions for use, for example, in lining steel furnaces.
• a refractory composition comprising a fine fraction, and optionally also a coarse fraction of a basic, neutral or acidic refractory material, the composition further comprising a dry chemically inert absorbent material having absorbed therein a liquid chemical bonding agent in amount sufficient to react with at least a proportion of the fine fraction of refractory material and bond the refractory composition together on. the addition of water.
• chemically inert is used in connection with the absorbent material to indicate that the said material does not react chemically with the refractory material in the conditions under which the composition is formulated.
• fine fraction in accordance with this invention is defined as a material substantially all of which passes a 25 B5. mesh sieve.
• the present invention further provides a chemically bonded refractory material whenever made from the composition described above, and also fired refractory structures whenever made from such chemically bonded materials.
• the refractory material may be for example alumina, dead-burned magnesite or chrome ore.
• the fine fraction of refractory material preferably passes a 72 BS. mesh sieve and usually constitutes from 10% to 100% of the refractory material, the coarser material constituting from 90% to 0% of the refractory material.
• a preferred form of the invention is one in which the refractory material contains a proportion of finely divided dead-burnt magnesite, preferably at least 25% by weight, which, on the addition of water, reacts with the liquid chemical bonding agent absorbed in the dry inert absorbent material.
• the finely divided dead-burned magnesite preferably passes a 72 mesh B.S. sieve.
• the inert absorbent material used for the liquid chemical bonding agent is preferably in the form of a finely divided powder, for example of kieselguhr, bentonite, fullers earth, chrome ore, or quartzite, or in the form of Patented Oct. 28, 1969 a mixture of such materials.
• the inert absorbent material may constitute for example up to 50% by weight, or more, of the composition. However the optimum amount in any particular case will depend on such factors as the liquid bonding agent used and the refractory material to be bonded. The optimum amount may readily be determined by routine experiment. The examples herein show satisfactory results with up to about 5% by Weight of inert material additionally containing liquid bonding agent.
• the combination of such a powder with the absorbed liquid chemical bonding agent is hereafter referred to as a bonding powder.
• the liquid chemical bonding agent is preferably an acid such as sulphuric acid, hydrochloric acid, chromic acid or phosphoric acid, but it may be for example a solution of a bonding agent other than an acid but which is known in the art as a chemical bonding agent for magnesia, for example a solution of a phosphate other than phosphoric acid, such as a sequestered phosphatic solution.
• the expression sequestered phosphatic solution has the meaning which is known in the art and refers to a commercial product containing dia'mmonium phosphate and polyphosphates. A more detailed description is found in British Patent No. 1,014,446 published Dec. 22, 1965.
• the amount of liquid bonding agent used may be for example from about 0.5% to 20% or more based on the total weight of the composition and up to for example 80% by weight based on the weight of the absorbent material. However the optimum amount may be readily determined in any particular case by routine experimentation.
• the amount of liquid bonding agent used is advantageously such that the quantity of agent present or produced on addition of water is between 0.5% and 1.5% of the weight of the refractory composition.
• Representative compositions may comprise, for example, from 25 to 40% by weight of dead-burned magnesite passing a British Standard 72 mesh sieve, from 60% to 75% by weight of dead-burned magnesite retained on a British Standard mesh sieve, and from 0.5 to 2.0% by weight of a product obtained by absorbing sulphuric acid in finely divided kieselguhr, the sulphuric acid being present in an amount of from 0.5% to 1.5% based on the total weight of the refractory composition.
• a preferred refractory composition contains 1% by weight of a sulphuric acid powder containing approximately 60% by weight of sulphuric acid.
• refractory composition Up to approximately 10% by weight of fine chrome ore may be incorporated in the refractory composition, a preferred quantity being 5%, and advantageously at least 2% by weight on the weight of the refractory composition consists of chrome ore particles finer than 30
• a small quantity, e.g. 0.5 to 2%, of boric acid is incorporated in the refractory composition a preferred quantity being 1% by weight.
• Refractory compositions made according to the following specification may be used advantageously as castable compositions in the repair of hot furnaces.
• the following case is given as an example.
• An L.D. converter used for the refining of iron by blowing oxygen on to molten metal is constructed with a at least 60% 150 mesh, and possessed a specific surface area of 0.2.7 mP/gm.
• Composition Sulphuric acid powder B Boric acid 1 Sulphuric acid powder A was a Kieselguhr powder with about 65% H1804 absorbed. l Sulphuric acid powder B was a Bentonite material with about 65% H 504 absorbed.
• Castable materials were prepared by mixing together. dead-burned maguesite of the composition and grading stated in Tables I and II respectively, and sulphuric acid powder, with additions of chrome ore and boric acid. The materials were mixed with sufiicient water to enable them to be cast and were then cast into test pieces. Details of the composition of the castable materials and the properties of the test pieces made from them are shown in Table IH.
• chrome ore suitable for use in refractory materials may be used.
• a further series of castable materials was made up using the same magnesia as before but with differing amounts of acid powder.
• composition and properties of the castables of this series are given in Table IV.
• Table VI shows that addition of 3 parts of chrome ore A results in the presence in the castable of 2.1 parts by weight of chrome ore particles smaller than 30 and addition of 5 parts of chrome ore B results in the presence of 2.0 parts by weight of chrome ore particles smaller than 30,. However, 5 parts by Weight of chrome ore C contain only 1.1 parts by weight of particles smaller than 30g.
• Fused alumina grain crushed to pass 7 BS. mesh together with 30% of ball-milled fused alumina was mixed with 7% of phosphoric acid powder (containing 70% free H PO and 11% gauging water. The mixture was cast into a block and cured at 2300 C. (As is normal with phosphoric acid bonded alumina material.) The resulting block possessed a cold compressive strength of about 2000 pounds per square inch.
• An acidic refractory composition was made from siliceous pebbles (containing 85-90% SiO which had been crushed to pass a 7 3.8. mesh and included about 20% of ball milled pebbles as the fine fraction. Approximately 2% by weight of fine magnesia was incorporated together with 1% sulphuric acid powder. On mixing with 7% gauging water and casting into a block the block In the latter two cases an important part of the bonding action was the reaction between the small quantity of magnesia and the acid powder when water i added. The mixtures are still essentially neutral and acid respectively, in nature in spite of the small addition of fine magnesia.
• compositions of the present invention may be used as castable refractory materials.
• the compositions which are in the form of dry mixtures, may be mixed with water and placed in a furnace lining by ramming or by a gunning technique using, for example, a nozzle mix gun.
• a nozzle mix gun pneumatically conveys the dry free-flowing composition along a pipe, water being mixed with the dry composition immediately behind the discharge nozzle of the gun.
• the moistened material is normally ejected across and into the furnace and is deposited on the furnace structure where it sets and hardens.
• the amount of water which is added to such ramming and gunning compositions is generally different to that required to be added to the compositions of the present invention when they are used as castable materials.
• Table VIII Listed in Table VIII are seven types of bonding powders comprising various inert materials having absorbed therein various liquid chemical bonding agents, the percentages by weight of inert absorbent material and liquid bonding agent being stated in the case of each type of bonding powder.
• Table IX are shown the chemical and grading analyses of two types of magnesia, designated X" and Y,'which were used to make refractory compositions in accordance with the invention.
• Table X are shown the refractory properties obtained from three compositions, designated 1 to 3, of which 2" and 3 are compositions in accordance with the present invention, to which suitable quantities of water have been added, and Composition 1 is a composition not in accordance with the present invention, obtained by mixing the indicated quantities of Magnesia X, chromic anhydride and water. It will be noted that Compositions 2 and 3 show marked superiority in the compressive strength properties and also in the results for the refractoriness-under-load tests, when compared with Composition 1.
• Table XI shows the refractory properties obtained from four refractory compositions designated 4 to 7, of which 5 and 7are compositions in accordance with the present invention to which suitable quantities of water have been added, and Compositions 4- and 6 are merely mixtures of the indicated quantities of Magnesia Y and water with concentrated hydrochloric acid and orthophosphoric acid respectively.
• the refractory properties of the compositions made in accordance with the present invention namely Nos. 5 and 7 are comparable with Compositions 4 and 6 respectively which are not in accordance with the in- 7. vention.
• Compositions 6 and 7 which both comprise phosphoric acid result in relatively low strength chemically-bonded compositions. This is due to the fact that magnesia and phosphoric acid react very rapidly.
• the present invention provides a method of constructing or repairing refractory units of furnace linings which method comprises mixing a refractory composition as hereinbefore described with water so as to produce a chemically-bonded refractory
• phosphate-bonded gunning mixes are used a material.
• separate tank of sequestered phosphatic solution is com-
• the refractory compositlon comprises an inert ab? into the dry refractory material at the nozzle. It will be sorbent material having absorbed therein a liquid chemiappreciated that this procedure can be inconvenient.
• How- P bondlilg agent which 18 Preferably ip pi 9 ever by use of the present invention as exemplified above 10 9 feacilve t0 mflgileslte, i116 Composition bung ⁇ mind the phosphate solution or phosphoric acid may be in- Wlth Water at Q of P11311313c POZZIC P f cluded in the dry refractory composition, thus dispensing nd the resulting mixture being gunned into position in with the need for mixing the refractory material with the furnace structure so as to form a chemically-bonded a phosphate Solution at the mixing head of the nozzle refractory material integral with the furnacestructure.
• W111 be apPreclated that i Presfllt mvmufm as with water at the nozzle specifically described above provides an advantage in the TABLE VH1 convenience of mixing a single dry batch of refractory material only with water i.e. without the necessity for ggz s Inert Absorbent Material figg Chemical Balding adding a third ingredient in the form of a liquid chemical 7 Ki 1 uh 7 s 1 h 1 A id bonding agent such as an acid. A ..36 656 r upurc c B..- 36%; Fuller s Earth e4 7; Sulphuric Acid.
• repa1r of furnace structures consisting essentially of: G 58% Kieselguhr 42% fiydmchbmmd' (a) a refractory aggregate comprising fro 10% to TABLE 1X 100% of a fine fraction of solid, particulate, chemically-reactive refractory material with the remainder 1 Magnesmx Mane Y being a coarse fraction of refractory material, said Cheglbal analys pe 0 64 2 refractory aggregate being mixed with l 30 (1;) up to by weight, based on the composition,
• a dry, chemically inert, solid, particulate absorb- L99 ent material selected from the group consisting of 93.0? 5- 2% kleselguhr, bentonite, fullers earth, chome ore, quartzlte and mixtures thereof, said absorbent ma- 3; g; 35 terial having absorbed therein up to by weight, 12 12 based on the weight of the particulate absorbent as 36 material, of a liquid chemical bonding agent se-v Allsieves B.S.mesh.indicatespassing;+indicatesretaiuedon. lected from the group consisting of Sulphuric acid,
• composition Fired et1,65ii C. for 6 hours R.U.L. test, 10 C./min. Composition Dried at 120 C.
• a refractory composition as claimed in claim 1 which comprises in addition up to about 10% of finely divided chrome ore.
• a refractory composition consisting essentially of an admixture of:

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Cited By (17)

Citations (1)

• 1965
  • 1965-09-29 GB GB41393/65A patent/GB1123221A/en not_active Expired
• 1966
  • 1966-09-27 US US582228A patent/US3475188A/en not_active Expired - Lifetime
  • 1966-09-28 BE BE687476D patent/BE687476A/xx unknown
  • 1966-09-29 NL NL6613771A patent/NL6613771A/xx unknown
  • 1966-09-29 DE DE19661671111 patent/DE1671111A1/de active Pending

Patent Citations (1)

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